1. Field of the Invention
The present invention relates to a display device for a fuel cell vehicle for displaying the power operating condition of the fuel cell vehicle provided with a power source in the form of a generator-motor powered by a fuel cell and a chargeable and dischargeable energy storage.
2. Description of the Related Art
In recent years, with a view to protecting the environment, the development of fuel cell vehicles has been in progress which are provided with a power source in the form of a motor powered mainly by a fuel cell. Further, among the fuel cell vehicles so developed, there are ones which are provided with a chargeable and dischargeable energy storage as an auxiliary power source.
With this energy storage, energy can be supplied to the motor to assist the driving of the same motor, for example, when the vehicle is accelerated, whereas when the vehicle is decelerated, regenerative power can be recovered.
With the fuel cell vehicles, however, since there are generated less noise and vibration from the nature thereof when compared with conventional vehicles powered by an internal combustion engine, there is caused a problem that the driver has difficulty in grasping the operating conditions of the power sources.
In particular, since the energy storage is not directly involved in the operation of the motor, even if the energy storage fails to function properly, there occurs no direct problem with the operation of the vehicle. On the other hand, in case the vehicle is kept running with the energy storage malfunctioning, there is caused a problem that the load applied to the fuel cell becomes large. Consequently, letting the driver be aware of the management status of lost and gained electric energy (energy management) becomes an important point for the fuel cell vehicles.
An object of the present invention is to provide a display device for a fuel cell vehicle provided with a power source in the form of a generator-motor powered by a fuel cell and a chargeable and dischargeable energy storage wherein the fuel cell and the energy storage are monitored at all times so as to facilitate the grasping of the energy management for the fuel cell vehicle.
With a view to solving the problems, according to a first aspect of the present invention, there is provided a display device (for example, a meter device 20 in an embodiment) for a fuel cell vehicle provided with a power source in the form of a generator-motor (for example, a motor 10 in the embodiment) powered by a fuel cell (for example, a fuel cell 2 in the embodiment) and a chargeable and dischargeable energy storage (for example, a capacitor 5 in the embodiment), the display device comprising an output meter (for example, a motor output meter 25 in the embodiment) of the generator-motor and a capacitometer (for example, a capacitor capacitometer 26 in the embodiment) of the energy storage.
According to the construction, the output of the generator-motor when it is driven and the residual capacity of the energy storage can be indicated in an interlocked fashion, whereby the output and the residual capacity can be monitored together.
According to a second aspect of the present invention, there is provided a display device for a fuel cell vehicle as set forth in the first aspect of the present invention, wherein the output meter indicates an output of the fuel cell and an output of the energy storage separately in different colors.
According to the construction, of the driving output of the generator-motor, a ratio between a portion occupied by the output by the power of the fuel cell and a portion occupied by the output by the power of the energy storage can be indicated separately.
According to a third aspect of the present invention, there is provided a display device for a fuel cell vehicle as set forth in the first or second aspect of the present invention, wherein the capacitometer indicates a regenerative power and a residual capacity of the energy storage separately in different colors.
According to the construction, a ratio between the regenerative power and the residual capacity of the energy storage can be indicated understandably.
Further, with a view to solving the problems, according to a fourth aspect of the present invention, there is provided a fuel cell vehicle comprising: a generator-motor as a power source which is powered by a fuel cell and a chargeable and dischargeable energy storage; and a display device having an output meter of said generator-motor and a capacitometer of said energy storage.
According to a fifth aspect of the present invention, there is provided a fuel cell vehicle as set forth in the fourth aspect of the present invention, wherein the output meter indicates an output of said fuel cell and an output of said energy storage separately in different colors.
According to a sixth aspect of the present invention, there is provided a fuel cell vehicle as set forth in the fourth aspect of the present invention, wherein the capacitometer indicates a regenerative power and a residual capacity of said energy storage separately in different colors.